blk-mq: Introduce blk_mq_reinit_tagset

The new nvme-rdma driver will need to reinitialize all the tags as part of
the error recovery procedure (realloc the tag memory region). Add a helper
in blk-mq for it that can iterate over all requests in a tagset to make
this easier.

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Tested-by: Ming Lin <ming.l@ssi.samsung.com>
Reviewed-by: Stephen Bates <Stephen.Bates@pmcs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Tested-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 26 insertions, 0 deletions

diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index 56a0c37a3d06..729bac3a673b 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -485,6 +485,32 @@ void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset,
 }
 EXPORT_SYMBOL(blk_mq_tagset_busy_iter);
 
+int blk_mq_reinit_tagset(struct blk_mq_tag_set *set)
+{
+        int i, j, ret = 0;
+
+        if (!set->ops->reinit_request)
+                goto out;
+
+        for (i = 0; i < set->nr_hw_queues; i++) {
+                struct blk_mq_tags *tags = set->tags[i];
+
+                for (j = 0; j < tags->nr_tags; j++) {
+                        if (!tags->rqs[j])
+                                continue;
+
+                        ret = set->ops->reinit_request(set->driver_data,
+                                                tags->rqs[j]);
+                        if (ret)
+                                goto out;
+                }
+        }
+
+out:
+        return ret;
+}
+EXPORT_SYMBOL_GPL(blk_mq_reinit_tagset);
+
 void blk_mq_queue_tag_busy_iter(struct request_queue *q, busy_iter_fn *fn,
                 void *priv)
 {